On 26/02/2025 14:29, Nikita Travkin wrote:
While considering to propose WoA EL2 dt overlays upstream I was looking
at existing overlays and noticed that some of them are broken: they put
seemingly meaningful fixups into the overlay's "/" node, which places
them into the overlay "metadata" itself, not into a fixup fragment to be
applied to the actual dtb. This series fixes those two by changing to
full path "&{/}" which should work as it was initially intended.
See demonstration of the problem below:
$ cat base.dts
/dts-v1/;
/ {
compatible = "fake,board";
fake,value = <42>;
};
$ cat extra.dtso
/dts-v1/;
/plugin/;
/ {
foo;
bar { baz; };
};
&{/} { whatever-comes-next-after-baz; };
$ dtc base.dts -o base.dtb
$ dtc extra.dtso -o extra.dtbo
$ fdtoverlay -i base.dtb -o combine.dtb extra.dtbo
$ dtc base.dtb
/dts-v1/;
/ {
compatible = "fake,board";
fake,value = <0x2a>;
};
$ dtc extra.dtbo
/dts-v1/;
/ {
foo;
bar {
baz;
};
fragment@0 {
target-path = "/";
__overlay__ {
whatever-comes-next-after-baz;
};
};
};
$ dtc combine.dtb
/dts-v1/;
/ {
whatever-comes-next-after-baz;
compatible = "fake,board";
fake,value = <0x2a>;
};
In the resulting dtb foo bar and baz are missing.
Signed-off-by: Nikita Travkin <nikita@xxxxxxx>
---
Nikita Travkin (2):
arm64: dts: qcom: qrb5165-rb5-vision-mezzanine: Fix broken overlay root
arm64: dts: qcom: sdm845-db845c-navigation-mezzanine: Fix the overlay root
arch/arm64/boot/dts/qcom/qrb5165-rb5-vision-mezzanine.dtso | 2 +-
arch/arm64/boot/dts/qcom/sdm845-db845c-navigation-mezzanine.dtso | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
---
base-commit: 8433c776e1eb1371f5cd40b5fd3a61f9c7b7f3ad
change-id: 20250226-qcom-nonroot-overlays-bfe21d33be8c
Best regards,
This is a good find however, we should just drop these additional CMA
heap nodes as the reason for their original addition has been superseded.
libcamera can now use UDMA buf for the same purpose as the CMA heap,
without the security concerns of CMA to distros.
You only need the CMA heap when you require uncached physically
contiguous buffers - for example Hantro on iMX but, this is not the case
on qcom hardware.
We can safely drop these CMA nodes for CAMSS.
---
bod
